The present invention relates to a scramble system for use in satellite broadcasting of text and graphical information, such as that which might be found in a typical newspaper, magazine or book.
In, for instance, a pay television broadcasting system(or a music/audio program broadcasting system) by way of a broadcasting satellite, programs are often scrambled, or encoded for broadcast so as to prevent these programs from being illegally intercepted by unauthorized parties. A person who wishes to become an authorized viewer/listener, or contractor(subscriber), of such a pay television program typically must contract with a programming service provider for such service. Upon contracting for service, the subscriber typically receives a scramble key (decrypt key) or code, so that he/she may descramble the scrambled program to legally listen to the pay TV program.
Nowadays, so-called xe2x80x9cCOATECxe2x80x9d system and the xe2x80x9cSKYPORTxe2x80x9d system have been practically utilized as a scramble system in pay television broadcasting via broadcasting satellites.
Recently, as a data broadcasting system for electronically distributing data such as newspaper (news data or newspaper data), such a broadcasting system has been proposed that newspaper data is inserted into a satellite data channel, and the resultant data is transmitted through the broadcasting satellite. In this case, for instance, at a data receiving apparatus installed in a contractor""s (subscriber""s)home/reception location who has made the newspaper data distribution contract with the newspaper data supplied, a signal transmitted through a satellite is received to derive the newspaper data inserted into the data channel. Then, this newspaper data is recorded on such a recording medium as a magnetic disk and a magneto optical disk and is read out therefrom if necessary. The read newspaper data is represented on, for instance, a display unit, or printed out, so that the contractor can read the newspaper.
In other words, according to the above-described scramble system since the programs are transmitted by only selecting one of the two transmission data processing methods, namely by scrambling the program data or by processing the program data in the non-scramble manner, merely uniform program service may be provided so that all of the contractors can observe the specific newspaper data and is not possible that some contractors cannot observe this specific newspaper data.
Currently existing services provide subscribers with textual news data via computer network. Such information is typically provided to the subscribers regardless of the subscribers"" interest or desire in receiving all types of news data. In other words, when subscribers subscribe to such a news service they receive, or have access to, all news data of all types or categories, regardless of their desire to receive or not receive certain news data. In essence, the subscriber typically pays for more news data than they actually use or receive. As a result, all of the contractors must pay their service fees regardless of whether or not they actually observe the broadcasted newspaper data. Accordingly, in the view of the contractors, they must pay not only the service fees for the necessary newspaper data, but also the service fees for the unnecessary newspaper data, so that they may feel an unfair fee payment system. This unfair fee payment system could impede promotion of the program contract, and furthermore could lower the profit of the information suppliers.
In the above-described scramble system, a scramble key is required to decrypt the scrambled program when the scrambled program is received. As a consequence, for instance, if the newspaper data (namely, scrambled newspaper data) have been received prior to the establishment of a contract are recorded on the recording medium, after the establishment of the contract, even if the contractor may have his own scramble key, he cannot decrypt the scrambled newspaper data which have been recorded on this recording medium.
The present invention has been made to solve these problems, and therefore, has an object to provide a scramble apparatus and a descramble apparatus, which are suitable for a data broadcasting system, and therefore are capable of providing various sorts of services.
The present invention is directed to providing satellite or cable broadcast of, for example, news data such as that which is commonly available in a printed form such as, for example, a newspaper or magazine. This news data may be of various forms, including textual data or photographic/image data. Further, in the present invention, information such as sound clips, or audio, as well as full motion video data, can be transmitted as news data.
As with typical printed publications, the present invention contemplates that news data, of whatever form, be classified, or categorized, into various types/categories of news data. For example, news data relating to sports information may be categorized as xe2x80x9csportsxe2x80x9d data or news data relating to business information may be categorized as xe2x80x9cbusinessxe2x80x9d data. Likewise, news data may be classified/categorized by the source or publisher of the news data. Of course any other number of categories can be defined and used to classify news data as needed.
The present invention seeks to allow a subscriber, or authorized party, to receive news data via, for example, broadcast satellite transmission, in a manner which precludes reception of any transmitted news data by unauthorized parties and further, precludes parties authorized to receive some types of news data from receiving other available types of news data which they have not subscribed to receive or paid for.
The present invention provides for a method of transmitting data, such as news data via an electronic network such as a broadcast satellite system, or cable television network, local area network, or the like. The method of the present invention includes assemblying news data, on a transmission side, news data and categorizing the news data into various predetermined categories (types). The categorized news data is then stored into a storage medium such as a computer storage memory. The computer storage memory may constitute an optical disk hard drive or magnetic tape or disk medium. The categorized news data is then retrieved from the storage medium. Each type of news data is encoded according to a unique predetermined encyption key (first key data) associated with each type of news data. That is, each type of news data is encoded/encrypted with different first key data. Then, the encoded (or encrpyted) news data is encoded again using a second predetermined encryption key (second key data). This second encyption key, however, is common to all types of news data. The twice encoded news data is then transmitted via, for example, a broadcast satellite to a receiver. Upon reception of the broadcast signal, the twice encoded news data is de-crypted (decoded) using the common (or second) encryption key data used to encrypt the encoded news data prior to transmission. As a result the encrypted news data is yeilded. Next, the encrypted news data is decoded using the unique (or first)encryption key data used to encode news data prior to transmission. As a result, fully decoded news data is yeilded which may then be viewed/accessed in proper format by the subscriber. In the preferred embodiment, the second encryption key data is made available only to the receiver side of authorized subscribers and the first encryption key data is available to authorized subscribers who have subscribed to receive a particular type/category of news data.
A scramble apparatus according to the present invention comprises and entire scramble means (e.g., data scrambler 14 shown in FIG. 3) for scrambling an entire portion of the data, and block unit scramble means (e.g., information unit scramble processing unit 27 shown in FIG. 2) for selectively scrambling the data in a preselected block unit.
In this scramble apparatus, the entire portion of data scrambled in a preselected block unit by the block unit scramble means can be scrambled by the entire scramble means. When the data is constructed of data in a preselected file unit, this data can be scrambled in the file unit by the block unit scramble means.
One embodiment of this descramble apparatus is characterized by comprising an entire descramble means (e.g., data scrambler 87 shown in FIG. 5) for descrambling the entire portion of data scrambled by the entire scramble means, and block unit descramble means (e.g., information unit scramble processing unit 31 of FIG. 6) for descrambling the data scrambled in a predetermined block unit by the block unit scramble means.
In this descramble apparatus, when this apparatus further includes storage means (e.g., recording medium 8 shown in FIG. 6) for storing the data descrambled by the entire descramble means, the data stored in the storage means is descrambled by the block unit descramble means. When this apparatus further includes read means (e.g., IC card interface apparatus 111 shown in FIG. 11) for reading a scramble key from the storage medium for storing the scramble key used to descramble the data scrambled in the predetermined block unit by the block unit scramble means, the data can be descrambled by the block unit descramble means with employment of the scramble key read from the read means.
When this apparatus further includes ID storage means (memory 83 shown in FIG. 5) for storing the unique ID, and also the storage medium stores a preselected ID in addition to the scramble key, the scramble key is allowed to be read from the storage medium only if the ID stored in the ID storage means is coincident with the ID stored in the storage medium.
In accordance with the scramble apparatus of the present invention, the data is selectively scrambled in a predetermined block unit, and further the entire portion of data are scrambled. As a consequence, it is possible to provide only desirable data to the proper contractor.
In accordance with the descramble apparatus of the present invention, the entire portion of scrambled data is descrambled, and further the data scrambled in a preselected block unit is descrambled with respect to this data. Accordingly, the contractor can receive only his desirable data.